Could a Single Vaccine Work Against All Coronaviruses?
The invention of Covid-19 vaccines will be remembered as a milestone in the history of medicine, creating in a matter of months what had before taken up to a decade. But Dr. Kayvon Modjarrad, the director of Emerging Infectious Diseases Branch at Walter Reed Army Institute of Research in Silver Springs, Md., isn’t satisfied.
“That’s not fast enough,” he said. More than 2.3 million people around the world have died, and many countries will not have full access to the vaccines for another year or two: “Fast — truly fast — is having it there on day one.”
There will be more coronavirus outbreaks in the future. Bats and other mammals are rife with strains and species of this abundant family of viruses. Some of these pathogens will inevitably spill over the species barrier and cause new pandemics. It’s only a matter of time.
Dr. Modjarrad is one of many scientists who for years have been calling for a different kind of vaccine: one that could work against all coronaviruses. Those calls went largely ignored until Covid-19 demonstrated just how disastrous coronaviruses can be.
Now researchers are starting to develop prototypes of a so-called pancoronavirus vaccine, with some promising, if early, results from experiments on animals. Dr. Eric Topol, a professor of molecular medicine at the Scripps Research Institute in San Diego, thinks scientists should join together in another large-scale vaccine-creation project immediately.
“We have to get a real work force to accelerate this, so we can have it this year,” he said. Dr. Topol and Dennis Burton, a Scripps immunologist, called for this project on broad coronavirus vaccines on Monday in the journal Nature.
After coronaviruses were first identified in the 1960s, they did not become a high priority for vaccine makers. For decades it seemed as if they only caused mild colds. But in 2002, a new coronavirus called SARS-CoV emerged, causing a deadly pneumonia called severe acute respiratory syndrome, or SARS. Scientists scrambled to make a vaccine for it.
Since no one had made a coronavirus vaccine for humans before, there was a huge amount to learn about its biology. Eventually, researchers chose a target for immunity: a protein on the surface of the virus, called spike. Antibodies that stick to the spike can prevent the coronavirus from entering cells and stop an infection.
Public health officials in Asia and elsewhere did not wait for the invention of a SARS vaccine to get to work, however. Their quarantines and other efforts proved remarkably effective. In a matter of months, they wiped out SARS-CoV, with only 774 deaths along the way.
The danger of coronaviruses became even clearer in 2012, when a second species spilled over from bats, causing yet another deadly respiratory disease called MERS. Researchers started work on MERS vaccines. But some researchers wondered if making a new vaccine for each new coronavirus — what Dr. Modjarrad calls “the one bug, one drug approach” — was the smartest strategy. Wouldn’t it be better, they thought, if a single vaccine could work against SARS, MERS and any other coronavirus?
That idea went nowhere for years. MERS and SARS caused relatively few deaths, and were soon eclipsed by outbreaks of other viruses such as Ebola and Zika.
In 2016, Maria Elena Bottazzi, a virologist at Baylor College of Medicine, and her colleagues applied for support from the American government to develop a pancoronavirus vaccine, but did not receive it. “They said there’s no interest in pancorona,” Dr. Bottazzi recalled.
Her team even lost funding for developing a SARS vaccine after they showed that it worked in mice, was not toxic to human cells and could be manufactured at scale. A coronavirus that had disappeared from view simply wasn’t a top priority.
Without enough money to start clinical trials, the scientists stored their SARS vaccine in a freezer and moved on to other research. “It’s been a struggle,” Dr. Bottazzi said.
Dr. Matthew Memoli, a virologist at the National Institute of Allergy and Infectious Diseases, looks back at those decisions as an enormous blunder. “It’s a failure of our system of science,” he said. “Funders tend to chase after shiny objects.”
Three years later, a third dangerous coronavirus emerged: the SARS-CoV-2 strain that causes Covid-19. Although this virus has a much lower fatality rate than its cousins that cause SARS and MERS, it does a far better job of spreading from person to person, resulting in more than 106 million documented cases around the world and still climbing.
All the lessons that researchers had learned about coronaviruses helped them move quickly to make new vaccines for SARS-CoV-2. Dr. Bottazzi and her colleagues used the technology they had created to make SARS vaccines to make one for Covid-19, which is now in early clinical trials.
Other researchers used even newer methods to move faster. The German company BioNTech created a genetic molecule called messenger RNA that encoded the spike protein. Partnering with Pfizer, the companies received U.S. government authorization for their vaccine in just 11 months. The previous record for a vaccine, against chickenpox, was four years.
Although the Covid-19 pandemic is still far from over, a number of researchers are calling for preparations for the next deadly coronavirus.
“This has already happened three times,” said Daniel Hoft, a virologist at Saint Louis University. “It’s very likely going to happen again.”
Coronavirus Vaccine Tracker
A look at all the vaccines that have reached trials in humans.
Researchers at VBI vaccines, a Cambridge-based company, took a small step toward a pancoronavirus vaccine last summer. They created virus-like shells studded with spike proteins from the three coronaviruses that caused SARS, MERS and Covid-19.
When the researchers injected this three-spike vaccine into mice, the animals made antibodies that worked against all three coronaviruses. Intriguingly, some of those antibodies could also latch onto a fourth human coronavirus that causes seasonal colds — even though that virus’s spike proteins were not included in the vaccine. The scientists have made this data public but have not yet published it in a scientific journal.
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What You Need to Know About the Vaccine Rollout
- Providers in the U.S. are administering about 1.3 million doses of Covid-19 vaccines per day, on average. Almost 30 million people have received at least one dose, and about 7 million have been fully vaccinated. How many people have been vaccinated in your state?
- The U.S. is far behind several other countries in getting its population vaccinated.
- In the near future, travel may require digital documentation showing that passengers have been vaccinated or tested for the coronavirus.
- When can you get the vaccine? What are the vaccine’s side effects? Is it safe to take during pregnancy? We’ve have answers to many of your questions.
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